Various types of the above-mentioned binary aluminum alloy are known.
However, the strength to be attained according to the process of dissolution, heat treatment or working heat treatment described in Patent References 12 and 13 is limited.
As confirmed from the descriptions in Patent References 1 to 13, no one could obtain a bulky high-strength alloy comprising only two constitutive elements and having a strength on a level of 1 GPa or so.
For enhancing the strength, Patent References 1 to 5 and 8 to 11 describe incorporation of a rare earth element, but use of an element much rarer than iron is defective in that it detracts from versatility.
The aluminum alloy described in Patent References 1 and 2 has a relatively high strength but has a form of rapid-quenched thin ribbon, and at present, therefore, its practicability is low, and for its practical use, it must be bulky.
Patent References 3 and 4 describe a technique of making the rapid-quenched thin ribbon bulky, but the process is extremely complicated and is impracticable.
The oxidation treatment of the powder in the process of producing an alloy powder described in Patent References 6 and 7 has a risk of greatly detracting from the ductility of the alloy.
Further, regarding the addition of a dispersant described in Patent Reference 7, it may greatly detract from the mechanical properties, especially the ductility of the alloy when the amount thereof added is excessive. Regarding the technology of preliminary shaping and SPS described in Patent Reference 12, the alloy is shaped into a shaped article in the subsequent superplastic forging step though it is processable in near-net-shaping, and therefore this could not fully utilize the advantage of SPS. In the electron beam vapor deposition method described in Patent References 11 and 13, the thickness of the alloy formed is difficult to increase.
The alloy described in Patent References 1 to 5 and 9 has an amorphous or semi-crystalline, non-equivalent structure, and therefore its structure stability at high temperatures is poor.    Patent Reference 1: JP-A 5-331584    Patent Reference 2: JP-A 5-331586    Patent Reference 3: JP-A 1-275732    Patent Reference 4: JP-A 6-41702    Patent Reference 5: JP-A 6-184712    Patent Reference 6: JP-A 7-268401    Patent Reference 7: JP-A 9-31567    Patent Reference 8: JP-A 8-232032    Patent Reference 9: JP-A 9-111313    Patent Reference 10: JP-A 6-17180    Patent Reference 11: JP-A 8-283921    Patent Reference 12: JP-A 11-209839    Patent Reference 13: JP-A 2003-277866